Process for preparing aripiprazole oral soluble film

ABSTRACT

The present invention is directed to an aripiprazole oral soluble film and a preparation method thereof. The aripiprazole oral soluble film comprises 10-60% w/w of aripiprazole in a crystalline state and 30-95% w/w of one or more film-forming materials, wherein 90% of the aripiprazole particles have a size of ≤14.3 μm and are uniformly blended in the film without visible undispersed particles. The aripiprazole oral soluble film has excellent bioavailability, uniformity, stability, and palatability. The oral soluble film preparation is prepared by first grinding aripiprazole particles to have desired small particle sizes, then blending the aripiprazole particles with film forming materials in an aqueous solution to a uniform suspension, defoaming the suspension, and coating the suspension on a substrate and drying it to form a film.

This application is a divisional of U.S. application Ser. No. 17/087,949, filed Nov. 3, 2020; which claims the priority of Chinese Application No. 202010995622.8, filed Sep. 21, 2020; which is incorporated herein by reference in its entirety.

FIELD OF INVENTION

The present invention relates to an oral soluble film for delivery of aripiprazole. The oral film contains aripiprazole particles in a low micron size and is a crystalline state. The oral film provides rapid dissolution of aripiprazole in mouth and is flexible and uniform in appearance.

BACKGROUND OF THE INVENTION

Schizophrenia is a common type of mental illness with delusions, hallucinations and complete separation from others. Schizophrenia is more prevalent than Alzheimer's disease, multiple sclerosis, insulin-dependent diabetes, and muscular dystrophy. According to World Health Organization data, schizophrenia continues to have the highest prevalence of any serious mental illness, affecting about 7‰ of adults worldwide.

The earliest antipsychotic drugs such as chlorpromazine, haloperidol, perphenazine, and sulpiride are known as typical or first-generation antipsychotic drugs (FGA). This type of drugs is gradually being replaced by second-generation antipsychotic drugs (SGA). SGA is also known as an atypical antipsychotic drug and is represented by clozapine, olanzapine, and risperidone, which are significantly better than the first-generation antipsychotic drugs in terms of safety and tolerability. However, long-term use of SGA can lead to weight gain and an increased tendency for abnormal lipid and glucose metabolism, thus leading to poor patient compliance with medication.

Aripiprazole, as the world's first partial dopamine agonist, can regulate dopamine levels without completely blocking the dopamine D2 receptor, and is also known as “third-generation antipsychotic drug” (TGA). It has clinical characteristics such as fast onset, high safety and good tolerance while having little effect on the levels of blood glucose, body weight and prolactin, so it can effectively improve the patient's compliance with long-term medication.

The currently marketed dosage forms are mainly ordinary tablets, orally disintegrating tablets, capsules, and long-acting injections. Due to the particularity of the patient population, the swallowing compatibility with ordinary tablets and capsules is poor, which limit patient compliance. As for the orally disintegrating tablets, the disadvantages include complicated preparation process, a large amount of excipients, high cost, low hardness, special packaging, inconvenient transportation and storage, and a grit feeling after oral administration. Long-acting injections have the problems of high production cost, inconvenient transportation and storage, and low patient compliance.

As a new oral drug delivery system, an oral soluble film is convenient to carry and use. It is suitable for patients who have difficulty in swallowing, which improves patient compliance. As a new dosage form, the form is attractive to patients who have difficulties with previously available options. Its unique method of administration can also greatly avoid concealment and vomiting by mental patients, and has advantages in the clinic.

The challenge in developing aripiprazole into an oral film is the low solubility of aripiprazole, content uniformity and discomfort (bitter taste) after film disintegration.

It has been reported that β-cyclodextrin is incorporated into injection solution to improve the solubility. However, the limited drug loading of the oral soluble film is insufficient to achieve the drug required amount.

U.S. Pat. No. 9,694,008 discloses an orally fast dissolving film formulation comprising aripiprazole or a pharmaceutically acceptable salt thereof and an organic acid, wherein: the film formulation has a pH in the range of 4.95 to 5.18; the aripiprazole or the pharmaceutically acceptable salt thereof and the organic acid have a weight ratio in the range of 2:1 to 66:1; the organic acid is citric acid. The '008 patent uses organic acids to control the pH within a narrow range of 4.95 to 5.18 to improve solubility. Such narrow pH range is difficult to control for manufacturing. Different saliva levels of different individuals also influence on the and affect the drug release rate in individuals.

There exists a need for a new and improved oral soluble film of aripiprazole, which achieves ideal dissolution, uniformity, stability, scalability, and patient compliance.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides aripiprazole oral soluble film with improved drug dissolution, uniformity, and taste. The inventors have discovered that by controlling the aripiprazole particle size and the crystalline state in the oral film, the film provides a desirable aripiprazole dissolution rate in the oral cavity and a comparable bioavailability to that of an aripiprazole tablet. The film has a good stability and a desirable taste. The aripiprazole oral soluble film is placed in the oral cavity of a subject, dissolved in saliva, and then swallowed and absorbed in the gastrointestinal tract.

The oral soluble film of the present invention uses small particle size of aripiprazole (D₉₀: 14.3 μm) to maximize the specific surface area to achieve rapid dissolution, without adding plasticizers, stabilizers, surfactants, or clathrates into the formulation. The production process does not require an organic solvent which improves to environmental protection and safety. Since the particle size is extremely small, the film does not produce a sense of grain and provides a good palatability.

The aripiprazole oral soluble film of the present invention comprises 0.5-70% w/w of aripiprazole in a crystalline state and 25-96% w/w of one or more film-forming materials, wherein 90% of the aripiprazole particles have a size of <14.3 μm and are uniformly blended in the film without visible undispersed particles.

The aripiprazole oral soluble film comprises aripiprazole, or a pharmaceutically acceptable salt thereof, in a small particle size of D₉₀ being 14.3 μm. “D₉₀” as used herein, means 90% of the particles have a diameter below the recited value. For example, D₉₀ of 14.3 μm means that 90% of the particles have a diameter below 14.3 μm.

The commercially available aripiprazole typically has a particle size of 65-100 μm. When aripiprazole with a particle size of D₉₀: 30 to 100 μm was used to prepare an oral soluble film, the film was non-uniform in appearance due to drug sedimentation during film formation; the film had an unacceptably slow dissolution rate and a grit-like taste when it was dissolved in mouth.

Aripiprazole in the oral soluble film in general is in an amount of about 10-70% w/w, preferably about 10-65%, or about 15-65%, or about 20-65% w/w. The D₉₀ particle size of aripiprazole in general is about 14 μm, preferably about 12 μm or about 10 μm. “About” as used herein, refers to ±10% of the recited value. About 90% of aripiprazole particles in the oral soluble film have a size distribution of about 0.1-14 μm, about 0.1-12 μm, or about 0.1-10 μm.

Aripiprazole in the oral soluble film of the present invention is in a crystalline state. The inventors have discovered that when the drug substance aripiprazole is in an amorphous form, aripiprazole dissolves in the oral cavity too quickly and results in a bitter taste. Moreover, the stability of aripiprazole is reduced noticeably due to the amorphous form. The present invention combines the features of small particles and crystalline state of aripiprazole and provides an oral film with a good dissolution rate, a palatability, and a uniform and flexible film.

The film-forming materials useful in the pharmaceutical composition include, but not limited to, polyvinyl alcohol (PVA), hydroxypropyl cellulose (HPC), hydroxyethyl cellulose, hydroxypropyl methyl cellulose, hypromellose (HPMC), sodium carboxymethyl cellulose (CMC-Na), xanthan gum, pectin, copovidone, povidone, guar gum, pullulan, polyethylene oxide, sodium alginate, and chitosan. Preferred film-forming materials are polyvinyl alcohol, hypromellose, hydroxypropyl cellulose, hydroxyethyl cellulose, copovidone, povidone, pullulan, polyethylene oxide. More preferred film-forming materials are polyvinyl alcohol, hypromellose, hydroxypropyl cellulose, and hydroxyethyl cellulose. The weight percentage of film-forming materials is about 25-96%, 30-96%, 35-96%, 25-80%, 30-80%, or 35-80% w/w. The film-forming materials are compatible with aripiprazole and provide a suitable drug loading capacity.

In one embodiment, the film of the present invention further comprises a defoamer to improve the defoaming efficiency of film-forming solution and flexibility of the film. In general, the defoamer is in an amount of about 0.01-10% or 0.02-5% w/w, preferably about 0.05-5%, about 0.05-2%, about 0.05-1%, or about 0.1-0.5% w/w. In one embodiment, the defoamer is selected from the group consisting of dimethicone, simethicone, oleyl alcohol, and a combination thereof.

One or more coloring agents are optionally added to the film-forming materials to improve the color of the oral soluble film. The coloring agent, for example, are selected from the group consisting of FD&C colors, D&C colors, and combinations thereof.

One or more flavoring agents or taste masking agents are optionally added to improve the taste of the oral soluble film. The flavoring agent may include one or more ingredients as follows: sucrose, glucose, sodium saccharin, fructose, xylitol, stevia, aspartame, sucralose, neotame and acesulfame potassium, peppermint oil, menthol, orange flavor, pineapple flavor, cherry flavor, apple flavor, banana flavor, blueberry flavor, peach flavor, mango flavor, or grape flavor. Sucralose and menthol are preferred flavoring agents for the present invention. The amount of a flavoring agent in the composition is about 0.01-5%, preferably about 0.05-2% (w/w) in the film forming solution and in the film.

The oral film of the present invention does not include a plasticizer or a surfactant. Plasticizer are typically used to improve the flexibility of a film, and surfactants are typically used to increase the solubility of aripiprazole. Because the present invention uses small particles (D₉₀: 14 μm) of aripiprazole, the film forming solution has a good solubility of aripiprazole, and the film has a good flexibility without a plasticizer or a surfactant.

The oral film of the present invention does not include an organic solvent. Organic solvents are sometimes used to improve the solubility of aripiprazole. Because the present invention uses small particles (D₉₀: 14 μm) of aripiprazole, the film forming solution has a good solubility of aripiprazole without an organic solvent. In one embodiment, the oral film further does not include an organic acid such as citric acid.

The present invention is also directed to a process for preparing the aripiprazole oral soluble film. The process comprises the steps of: (a) grinding a starting material of aripiprazole by bead milling, air crushing, or colloid milling until 90% of the aripiprazole particles have a size of ≤14.3 μm, (b) blending the aripiprazole particles of (a) and one or more film-forming materials in an aqueous solution by a mechanical homogenization blending process at a speed of at least 1500 rpm, optionally further by plate- and frame blending, to prepare a uniform suspension, (c) defoaming the suspension; and (d) coating the defoamed suspension on a substrate and drying the suspension to form the film.

In step (a), a starting material of aripiprazole (typically having D₉₀ of 50-100 μm) was grinded until the aripiprazole particles reach desirable smaller sizes of D₉₀: 14.3 μm and maintain a crystalline state. Normal tooth mill, knife mill and high-pressure homogenization processes cannot obtain the required particle size, while bead milling, air-guided crushing and colloidal milling processes can reduce the particle size D₉₀ to 14.3 μm and maintain the original crystal form. A preferred mill process is bead milling with a scatter axis speed of ≥3000 rpm (e.g., 3000-6000 rpm) and milling cycles ≥3 cycles.

The issues of aripiprazole including slow dissolution rate, grit-like taste and stability problems can be resolved by a special milling process, but due to the strong electrostatic adsorption of small aripiprazole particles, they tend to adsorb together and aggregate into agglomerates. Furthermore, aripiprazole is a poorly soluble non-ionic compound, especially in the case of fine particle size with a large surface tension, it is difficult to have a even suspension. Step (b) resolves these problems.

In step (b), the aripiprazole particles of smaller sizes, one or more film-forming materials, and optionally a defoamer are blended in an aqueous solution by homogenization blending to prepare a uniform film-forming suspension. Different blending processes can lead to different blending uniformity. The conventional paddle blending, plate and frame blending, and paddle blending plus plate-and-frame blending do not achieve the required blending uniformity. However, homogenization blending or homogenization blending plus plate-and-frame blending fully disperses the aripiprazole crystal particle agglomerates to form a uniform suspension, without a need to add surfactants or emulsifiers. To form a homogeneous suspension, a preferred homogenization speed is at least 1500 rpm (e.g., 1500-4000 rpm or 1500-3000 rpm) and preferred homogenization time is at least 3 minutes (e.g., 3-20 minutes). Conduct a defoaming process to obtain the homogeneous film forming solution.

In step (c), the blended suspension of (b) is defoamed. In the formulation, aripiprazole is in the crystalline form with a high specific gravity, which leads to sedimentation during the defoaming process. Although, adding a suspending agent or thickening agent can slow down the settling rate, it also prolongs the defoaming time. Therefore, defoaming agents, which increase the surface tension and accelerate the bursting of bubbles, are preferably used together with vacuum defoaming technique to reduce the defoaming time. With preferred defoaming agents (e.g., dimethicone, simethicone, or oleyl alcohol) and vacuum defoaming process, the defoaming time is shortened by more than 8 h, while the film-forming ability and stability of the film is maintained. A defoaming agent may further hinder the sedimentation of aripiprazole, while improving the production efficiency and reducing production costs.

In step (d), the defoamed suspension is coated on a substrate such as a conveyer and is dried to form a film. The dried film is ready to be cut and packaged.

The advantages of the oral soluble film of the present invention are summarized below:

-   -   a. As the aripiprazole remains original crystal form and degree         of crystallinity, the stability of the drug substance is         maintained and no extra stabilizer is required in the         formulation.     -   b. The dissolution rate of aripiprazole is increased         dramatically: 85% or even 95% is dissolved within 5 minutes.     -   c. Due to the small particle size of the drug substance, the         sedimentation of aripiprazole during the solution preparing,         defoaming, coating and drying processes is effectively reduced.         Thus, desired uniformity can be achieved in the final film         product.     -   d. Combining with a homogenization process, the drug load         percentage is improved to 60% w/w without using any plasticizer.     -   e. As the particle size of the drug substance is extremely         small, no grit-like taste or any other uncomfortable feeling         develops after the film is dissolved in the oral cavity, which         improves taste.     -   f. The oral soluble film formed is flexible and not brittle         without the use of plasticizers.

The following examples further illustrate the present invention. These examples are intended merely to be illustrative of the present invention and are not to be construed as being limiting.

Examples Example 1: Aripiprazole Soluble Film (30-100 μm Particle Size with Crystalline State)

In this example, the aripiprazole (Particle Size D₉₀: 65.5 μm) was manufactured as a film dosage form, which can be administered orally. The formulation of this example is shown below.

Aripiprazole  5.0 mg (25% w/w) Hypromellose 14.6 mg (73% w/w) Titanium Dioxide  0.4 mg (2% w/w) Purified Water   45 mg (Removed during manufacturing process)

Preparation: Aripiprazole was dispersed into the solvent according to the formulation, then it was added with other components in the formulation, and blended until it was completely suspended by paddle blending process. The film solution was defoamed and evenly coated on the conveyor belt, and then dried at the temperature of about 50° C. to 80° C. Residual aqueous carrier was evaporated after drying. After the film was formed, it was cut into a suitable size and shape and packaged.

The aripiprazole soluble film prepared by the above method presented satisfactory film-forming performance and could be easily peeled off from the film base. Also, the films had smooth appearance and uniform color. Moreover, the active ingredient aripiprazole crystal powder was dispersed evenly in the film. An x-ray powder diffraction showed that the aripiprazole was in a crystallized state in the film.

In a dissolution test, the drug powder was released and dissolved after the oral film was dissolved, and the dissolution rate was relatively slow (41% at 5 min).

TABLE 1 Dissolution Test Result (Crystalline Aripiprazole) pH 4.0 sodium acetate buffer Media (1000 mL), basket method, speed: 75 rpm Time (min)  3 5 10 15 30 Dissolved (%) 27 41 68 76 98

Soluble films having different particle sizes (D90: 30-100 μm) of aripiprazole were prepared by the same method and tested by the dissolution test. The results show that aripiprazole in the produced soluble film was all in a crystalline state and was dispersed in the film as spots. Those soluble films also had a slow dissolution profile of 23%-72% at 5 min.

Example 2: Aripiprazole Soluble Film (Amorphous State)

In this example, the aripiprazole soluble film was prepared based on the method stated in Example 1. The formulation was modified to use methylene chloride instead of purified water. Aripiprazole used in the formulation was in a crystalline state, however, after the film was prepared, aripiprazole was converted into an amorphous state within the film, due to the use of methylene chloride in the formulation.

Aripiprazole  5.0 mg (25% w/w) Hypromellose 14.6 mg (73% w/w) Titanium Dioxide  0.4 mg (2% w/w) Methylene Chloride   45 mg (Removed during manufacturing process)

The aripiprazole soluble film prepared by this example had a smooth appearance and uniform color, without any noticeable crystal solid in the film. An x-ray powder diffraction test was conducted on this sample and suggested that the aripiprazole was in an amorphous state. Furthermore, the dissolution test showed that the drug substance was rapidly dissolved with 97% dissolved in 3 min.

TABLE 2 Dissolution Test Result (Amorphous Aripiprazole) pH 4.0 sodium acetate buffer Media (1000 mL), basket method, speed: 75 rpm Time (mm) 3 5 10 Dissolved (%) 97 99 100

In an accelerated stability experiment performed on the film, an undesired related substance (RS) F increased above the acceptance criteria 0.3%) after 3 months as shown in Table 3. Furthermore, because it was in an amorphous state, aripiprazole was fully and rapidly dissolved during dissolution of the film in the mouth, and the palatability was not good with a bitter taste. In addition, an organic solvent of methylene chloride was used during the process, which is not desirable.

TABLE 3 Accelerated Stability Result Accelerated Condition (40° C., 75% RH) Acceptance Criteria Example 2 0 day RS F ≤0.3% RS F: 0.03% RS G ≤0.3% RS G: 0.02% Total ≤1.0% Total: 0.08% 1 Month RS F: 0.17% RS G: 0.09% Total: 0.29% 3 Month RS F: 0.37% RS G: 0.19% Total: 0.57% *Note: RS F: USP Aripiprazole Related Compound F RS, C₂₃H₂₇Cl₂N₃O₃ RS G: USP Aripiprazole Related Compound G RS, C₂₃H₂₅Cl₂N₃O₂

Example 3: Aripiprazole Milling Processes

This experiment was to test particle size distribution of aripiprazole prepared by different milling processes.

In this experiment, aripiprazole with particle size distribution of D₉₀: 173.3 μm was used as a starting material. The starting material aripiprazole was grinded by different processes of tooth milling process, knife milling process, high-pressure homogenization process, air crushing process, colloid milling process, and bead milling process. The description and parameters of each process and the resulting particle size D₉₀ are shown in Table 4. The results show that among the milling processes tested, the bead milling process provided the smallest particle size of D₉₀: 1.3 μm. Air crushing and colloid milling also provided small particle size of D₉₀<10 μm.

TABLE 4 The Particle Size Distribution of Aripiprazole Obtained by Different Milling Processes Milling Tooth Knife High-Pressure Air Colloid Bead Processes Milling Milling Homogenization Crushing Milling Milling Process Through Through Forcing the Use high- Colloid Beads inside Description high-speed the high- materials at high speed mills work the grinding relative speed pressure through airflow to on the chamber are movement rotation of small holes, and make rotor-stator agitated by between the crush the materials particles principle: a rotating the the shearing into small particle impact, rotor turns shaft, and movable knife, the sizes collide, at high the particles toothed materials friction and speeds are ground plate and are crushed shear to by the the fixed by impact, achieve collision and toothed friction and crushing shear force plate, the impact of of the beads. materials materials. are crushed by impact and friction Process Milling at Milling for Homogenization Milling at Milling for Milling for 5 Parameters 3500 rpm 10 min at for 5 cycles at 5.0 kg/cm² 5 cycles at cycles at and sieved 25000 rpm 20000 Psi pressure air pressure 10000 rpm 6000 rpm with 250 and 2 L/h flow rate and 1 kg/h mush feed rate screen D₉₀ 56.41 μm 16.61 μm 38.9 μm 9.3 μm 7.2 μm 1.3 μm

Example 4: Aripiprazole Bead Milling Process with Different Process Parameters

This experiment is to test particle size distribution of aripiprazole prepared by beading milling with different process parameters.

In this experiment, aripiprazole with particle size distribution (D₉₀: 56.2 μm) was used as a starting material. The bead milling process was used for milling, with different process parameters (different spindle speed and numbers of grinding cycles) as shown in Table 5. When the spindle speed was ≥3000 rpm, and the number of grinding cycles was ≥3 cycles, a satisfactory particle size distribution (D₉₀≤8.3 μm) was obtained. With a lower spindle speed of 1500 rpm, but a higher number of grinding cycles of ≥5 cycles, a satisfactory particle size distribution (D₉₀≤14.3 μm) can also be obtained.

TABLE 5 The Particle Size Distribution of Aripiprazole Obtained by Different Process Parameters Process Spindle Speed 1000 rpm 1500 rpm 1500 rpm 1500 rpm 3000 rpm 3000 rpm 6000 rpm 6000 rpm Parameters Grinding cycles 20 3 5 10 3 5 3 10 D₉₀ 18.6 μm 23.5 μm 14.3 μm 10.2 μm 8.3 μm 4.7 μm 1.8 μm 0.5 μm

Example 5: Aripiprazole Soluble Film (0.5-18.6 μm Particle Size)

In this example, aripiprazole of different particle size D₉₀: 0.5 μm, 1.3 μm, 4.7 μm, 10.2 μm, 12.4 μm, 14.3 μm and 18.6 μm) was prepared by bead milling process. The soluble film was prepared via the method of Example 1, with the formulation below.

5-1 5-2 5-3 5-4 5-5 5-6 5-7 Particle Sizes (D₉₀) 0.5 μm 1.3 μm 4.7 μm 10.2 μm 12.4 μm 14.3 μm 18.6 μm Aripiprazole  5.0 mg (25% w/w) Hypromellose 14.6 mg (73% w/w) Titanium Dioxide 0.4 mg (2% w/w) Purified Water 45 mg (Removed during manufacturing process)

The aripiprazole soluble film prepared by the above method presented satisfactory film-forming performance and could be easily peeled off from the film base. Also, the films had a smooth appearance and uniform color, but there were some visible agglomerate particles on the film which were not completely evenly dispersed. An x-ray powder diffraction showed that the aripiprazole was in a crystallized state within the film.

The aripiprazole soluble films were tested by dissolution tests. The results show that when the particle sizes of D₉₀ were ≤14.3 μm, the dissolution was rapid, with ≥86% dissolved at 5 min (86%-100%).

TABLE 6 Dissolution Test Result Particle pH 4.0 sodium acetate buffer (1000 mL), basket Sizes method, speed: 75 rpm Dissolved (%) Test (D₉₀) 3 min 5 min 10 min Example 5-1  0.5 μm 96 100 100 Example 5-2  1.3 μm 95 100 99 Example 5-3  4.7 μm 90 97 100 Example 5-4 10.2 μm 85 93 99 Example 5-5 12.4 μm 82 91 97 Example 5-6 14.3 μm 77 86 95 Example 5-7 18.6 μm 64 81 91

An accelerated stability experiment was performed on film prepared according to Example 5-2; all related substances were well within the acceptance criteria during the accelerated period as shown in Table 7.

TABLE 7 Accelerated Stability Result Accelerated Condition (40° C., 75% RH) Acceptance Criteria Example 5-2 0 day RS F ≤0.3% RS F: 0.02% RS G ≤0.3% RS G: 0.01% Total ≤1.0% Total: 0.04% 1 Month RS F: 0.03% RS G: 0.02% Total: 0.05% 3 Month RS F: 0.03% RS G: 0.02% Total: 0.07% *Note: RS F: USP Aripiprazole Related Compound F RS, C₂₃H₂₇Cl₂N₃O₃ RS G: USP Aripiprazole Related Compound G RS, C₂₃H₂₅Cl₂N₃O

Example 6: Blending Processes

Because aripiprazole has a strong electrostatic adsorption, it easily aggregates into agglomerates. Further, aripiprazole is a poorly soluble nonionic compound and has a large surface tension in a submicron particle size, so it is not easy to suspend aripiprazole into an aqueous solution effectively and evenly. This example tested different blending methods and evaluate the blend uniformity.

In this example, aripiprazole (particle Size D₉₀: 1.3 μm) soluble film was prepared via the method according to Example 5-2, except with different blending processes, with the formulation below.

Aripiprazole  5.0 mg (25% w/w) Hypromellose 14.6 mg (73% w/w) Titanium Dioxide  0.4 mg (2% w/w) Purified Water   45 mg (Removed during manufacturing process)

Each aqueous aripiprazole formulation was blended by a different blending process of paddle blending, plate and frame blending, paddle blending plus plate-and-frame blending, and homogeneous blending plus plate-and-frame blending process. Homogeneous blending is conducted by a rotor/stator mixer. Through the high-speed and stable rotation of the rotor, high liquid shear, friction, extrusion, and collision are formed in the gap between the stator and the rotor, make the solid powder uniformly dispersed in the liquid. Homogenization blending is a preferred blending method for the present invention.

The uniformity test results are shown in Table 8. Blend uniformity is the uniformity of the suspension after blending. In this example, immediately after the blending process, 10 samples were taken from different locations of the blending tank and the aripiprazole amount of each sample was measured and the relative standard deviation (RSD) of blend uniformity was calculated.

RSD is calculated by the formula below:

${RSD} = {{\frac{S}{\overset{\_}{x}} \times 100\%} = {\frac{\sqrt{\frac{\sum_{i = 1}^{n}\left( {x_{i} - \overset{\_}{x}} \right)^{2}}{n - 1}}}{\overset{\_}{x}} \times 100\%}}$

Where S is standard deviation, X is arithmetic mean of all results, Xi is measured result of each sample, n is total number of samples.

The results of Table 8 show that a homogenization blending plus plate-and-frame blending process achieved a satisfactory blend uniformity in the aqueous suspension and provided a uniform film appearance.

TABLE 8 Uniformity Test Result Homogenization Paddle Blending Blending plus Plate and Frame plus Plate-and- Plate-and-Frame Blending Method Paddle Blending Blending Frame Blending Blending Process The motor drives The shape of the Combining paddle Combining Description the paddle to form plate and frame is blending and plate- homogeneous an axial liquid consistent with the and-frame blending and plate- flow, circulate the inner wall of the blending methods and-frame liquid and mix the tank, and the gap blending methods material from the inner wall is small, which is suitable for the stirring of medium and high viscosity liquids Process Parameters Blending for 30 Blending for 30 Blending for 30 Blending for 30 min at 1500 rpm min at 30 rpm min at paddle min at stirring speed of homogenization 1500 rpm and speed of 1500 rpm plate-and-frame and plate-and- stirring speed of 30 frame stirring rpm speed of 30 rpm Suspension State There are lot of There are few There are few Uniform agglomerates that agglomerates that agglomerates that suspension, no are not completely are not completely are not completely visible aggregate dispersed, and dispersed, and dispersed particles, no some powder is some powder is residual powder on floating on the floating on the the liquid surface surface of the surface of the mixing tank. mixing tank. Blend Uniformity 7.1% 5.8% 4.7% 0.8% in Suspension RSD* (n = 10) Appearance of Dry Has a lot of visible Has a few visible Has a few visible Uniform film Film agglomerated agglomerated agglomerated without visible particles on the particles on the particles on the undispersed film film film particles *Relative Standard Deviation [<3% is acceptable]

Example 7: Homogenization Process

In this example, the aripiprazole (Particle Size D₉₀: 1.3 μm) soluble film was prepared via the method of Example 5-2 with the formulation below, except with homogeneous blending plus plate- and frame blending.

Aripiprazole  5.0 mg (25% w/w) Hypromellose 14.6 mg (73% w/w) Titanium Dioxide  0.4 mg (2% w/w) Purified Water   45 mg (Removed during manufacturing process)

The blend uniformity test results from samples obtained under different process parameters is shown in Table 9. When the homogenization speed was ≥1500 rpm and the homogenization dispersion time was ≥3 min, the blend uniformity of the suspension met the requirement of RSD ≤3.0%.

TABLE 9 Uniformity Test Result homogenization speed 1000 rpm 1000 rpm 1500 rpm 3000 rpm 3000 rpm Process Stirring speed  20 rpm  20 rpm  20 rpm  20 rpm  20 rpm Parameters Time   3 min  10 min   3 min   3 min  20 min Suspension State Uniform Uniform Uniform Uniform Uniform suspension, suspension, suspension, suspension, suspension, no visible no visible no visible no visible no visible aggregate aggregate aggregate aggregate aggregate particles, no particles, no particles, no particles, no particles, no residual residual residual residual residual powder on powder on powder on powder on powder on the liquid the liquid the liquid the liquid the liquid surface surface surface surface surface Blend Uniformity in 4.2% 3.5% 2.3% 1.3% 0.6% Suspension RSD* (n = 10) Appearance of Dry Film Uniform Uniform Uniform Uniform Uniform film without film without film without film without film without visible visible visible visible visible undispersed undispersed undispersed undispersed undispersed particles particles particles particles particles *Relative Standard Deviation

Example 8: Aripiprazole Soluble Film (Film with Different Particle Sizes)

In this example, aripiprazole soluble films having different particle size (Particle Size D₉₀: 0.5-56.4 μm) were prepared via the method of Example 5, with the formulation below, except with homogeneous blending plus plate- and frame blending.

Aripiprazole 30.0 mg (60% w/w) Hydroxyethyl Cellulose   10 mg (20% w/w) Polyvinyl Alcohol   9 mg (18% w/w) Titanium Dioxide  0.5 mg (1% w/w) Sucralose  0.5 mg (1% w/w) Purified Water   50 mg (Removed during manufacturing process)

With the same formulation and process, the flexibility of the film varied greatly with different particle sizes of aripiprazole. The results are shown in Table 10. The results show that small particle size (D₉₀≤10.2 μm) of aripiprazole leads to a uniform and flexible film.

TABLE 10 Preparation of Solution Film with Dfferent Particle Sizes of Aripiprazole Particle Sizes 56.4 μm 38.9 μm 23.5 μm 10.2 μm 4.7 μm 0.5 μm (D₉₀) Suspension State Poor Poor Uniform Uniform Uniform Uniform uniformity, uniformity, have a lot of have few precipitate at the precipitate at the bottom bottom Blend Uniformity N/A 5.8% 3.8% 1.3% 0.7% 0.6% in Suspension RSD* (n = 10) Film Formed N/A Brittle Brittle Flexible Flexible Flexible Tensile N/A N/A 2 6 10 12 Strength(N/mm²) *Relative Standard Deviation

Example 9: Aripiprazole Soluble Film (Adding Defoamer)

In this example, aripiprazole (particle Size D₉₀: 4.7 μm) soluble film was prepared via the method according to Example 5-3, except with homogeneous blending plus plate- and frame blending.

Aripiprazole 10.0 mg (25% w/w) Hydroxyethyl Cellulose 20.0 mg (50.0% w/w) Copovidone  9.0 mg (22.0% w/w) Defoamer (Dimethicone, Colloidal 0.20 mg (0.5%) Silica, Simethicone, Lauric Acid, Oleyl alcohol, Palmitic Acid) Titanium Dioxide  0.8 mg (2% w/w) Purified Water   60 mg (Removed during manufacturing process)

With the same formulation and process, the defoaming efficiency of film forming solution and flexibility of the film varied greatly with different defoamers. The results are shown in Table 11. Dimethicone, simethicone, and oleyl alcohol all provided a good defoaming effect. In contrast, colloidal silica exhibited a poor defoaming effect, and lauric acid and palmitic acid made the film soft and sticky.

TABLE 11 Defoaming Time with Different Defoamers Colloidal Laurie Oleyl Palmitic Defoamer none Dimethicone Silica Simethicone Acid alcohol Acid Defoaming 16 h 4 h 13 h 5 h 7 h 6 h 7 h Time Film Formed Flexible Flexible Flexible Flexible Soft and Flexible Soft and Sticky Sticky

Example 10: Bioavailability of Aripiprazole Soluble Films

In this example, aripiprazole (particle Size D₉₀: 0.5 μm, 10.2 μm and 23.5 μm) soluble film was prepared according to Example 5, with the formulation shown in Table 12, except with homogeneous blending plus plate- and frame blending.

TABLE 12 Aripiprazole Formulation Example 10-1 10-2 10-3 Particle Sizes D₉₀ 23.5 μM 10.2 μm 0.5 μm Aripiprazole 10.0 mg (40% w/w) 10.0 mg (40% w/w) 10.0 mg (40% w/w) Hypromellose 20.0 mg (50.0% w/w) 20.0 mg (50.0% w/w) 20.0 mg (50.0% w/w) Hydroxyethyl Cellulose 3.92 mg (9.8% w/w) 3.92 mg (9.8% w/w) 3.92 mg (9.8% w/w) Newton 0.04 mg (0.1%) 0.04 mg (0.1%) 0.04 mg (0.1%) Dimethicone 0.04 mg (0.1%) 0.04 mg (0.1%) 0.04 mg (0.1%)   60 mg (Removed   60 mg (Removed during   60 mg (Removed during Purified Water during manufacturing manufacturing process) manufacturing process) process)

A human pharmacokinetic study was conducted on several volunteers. They were divided into 4 groups: (i) aripiprazole soluble films manufactured according to Examples 10-1, 10-2 or 10-3, 10 mg dosage; and (ii) aripiprazole oral tablets, 10 mg dosage. Aripiprazole oral tablets (ABILIFY®) were used as a gold standard for comparison. The blood samples were taken before administration (0 min), and 0.5 h, 1 h, 1.5 h, 2 h, 2.5 h, 3 h, 3.5 h, 4 h, 6 h, 8 h, 10 h, 12 h, 24 h, 48 h, 72 h, 96 h, 144 h, 192 h, 240 h after administration, respectively. The blood samples were then used to determine the aripiprazole plasma concentration via a sensitive and precise LC-MS/MS method and to calculate relative bioavailability of the soluble films. As shown in 3, each bioavailability of the soluble films prepared in Examples 10-1, 10-2, and 10-3 was 64%, 94%, and 108% of the oral tablets, respectively. Each T_(max) for these three examples was 3.5 h, 3.0 h and 2.3 h, respectively, and the T_(max) of tablets was 2.8 h.

The results show that by controlling the particle size, the bioavailability of aripiprazole in the body can be effectively improved, and at the same time, the peak time (T_(max)) can be shortened. When the particle size D₉₀≤10.2 μm, the bioavailability of aripiprazole oral soluble film was bioequivalent to aripiprazole tablets.

TABLE 13 Bioavailability Test with Different Films Pharmacokinetic Example Example Example parameter Tablets 10-1 10-2 10-3 Group Reference Test Group Test Group Test Group Mean T_(max) (h) 2.8 3.5 3.0 2.3 Mean C_(max) (ng/ml) 51.3 33.1 46.2 56.4 Mean AUC_(0-240h) 1118.8 713.2 1054.5 1213.7 (hr*ng/ml) Relatively — 64% 94% 108% bioavailability

The invention, and the manner and process of making and using it, are now described in such full, clear, concise and exact terms as to enable any person skilled in the art to which it pertains to make and use the same. It is to be understood that the foregoing describes preferred embodiments of the present invention, and that modifications can be made therein without departing from the scope of the present invention as set forth in the claims. To particularly point out and distinctly claim the subject matter regarded as invention, the following claims conclude this specification. 

What is claimed is:
 1. A process for preparing an aripiprazole oral soluble film comprising aripiprazole in a crystalline stat, comprising the steps of: (a) grinding a starting material of aripiprazole by a milling process until 90% of the aripiprazole particles have a size of ≤14.3 μm, wherein the aripiprazole maintain a crystalline state; (b) blending the aripiprazole particles of (a) and one or more film-forming materials in an aqueous solution by homogenization blending at a speed of at least 1500 rpm to prepare a uniform suspension, (c) defoaming the suspension; and (d) coating the defoamed suspension on a substrate and drying the suspension to form the film.
 2. The process according to claim 1, wherein the milling process is bead milling, air crushing, or colloid milling.
 3. The process according to claim 2, wherein the bead milling has a scatter axis speed of ≥3000 rpm and the milling cycles ≥3 cycles.
 4. The process according to claim 1, wherein the film-forming material is selected from the group consisting of hypromellose, polyvinyl alcohol, copovidone, povidone, hydroxyethyl cellulose, hydroxypropyl cellulose, and any combination thereof.
 5. The process according to claim 1, wherein the aqueous solution of step (b) does not contain an organic solvent.
 6. The process according to claim 1, where in step (b), the blending further comprises plate- and frame blending.
 7. The process according to claim 1, where in step (b), the aqueous solution further comprises a defoamer.
 8. The process according to claim 7, wherein the defoamer comprises dimethicone, simethicone, oleyl alcohol, or a combination thereof.
 9. The process according to claim 7, wherein deforming is a vacuum deforming. 